As a reviewer it is mandatory to go to play as early in the run as is possible. About 90% of the shows I see are on opening night. Again, the reason is obvious. My job is to inform people about the production to help them decide whether or not to manage their money by going (or not going) to the show. Running a review at the end of the run doesn't help that decision.
It can sometimes be a dilemma. I recently reviewed the Park Playhouse production of "The Producers." It was a technical nightmare. A loud hum was not only distracting, it was annoying. One of the leads had a microphone that frequently cut off just as he was delivering a punch line. There is little question such distractions bothered the audience; they also had to influence the performers confidence and comic timing.
In this case I made it clear in the review that on that night the tech problems ruined the performance. I also made it clear that it was unlikely someone reading the review would have those same problems. I understand a new sound system was installed the next day and there have been no more sound problems.
However, in a review I cannot be as generous to performances. There is no way of knowing with certainty how the technical problems affected the performances. There is a fine line between being aware of problems and apologizing for them. A reviewers job is to report on the production attended. Yes, we all assume a performance will improve throughout the run, but it is not always true. Besides, there were negative issues with some performances that had nothing to o with technical distractions.
I don't want to tell anyone to ignore my review of "The Producers," but I can say for sure, you will not see the show I saw.